External connections

The nRF52840 Dongle has 15 GPIOs in addition to the ground, power, and SWD connections
along the castellated edges.

The castellated edge holes have a pitch of 0.1 inches (2.54 mm) and a row spacing of 0.6 inches
(15.24 mm)1, making it suitable for stripboard connection. Test points
for additional nine GPIOs are available on the back side of the circuit board, leaving a total of
24 GPIOs accessible.

Note: There is no reverse voltage protection on the power connections.